//import java.util.Scanner;
//class DivisorIllegality extends RuntimeException{
//    DivisorIllegality(String msg){
//        super(msg);
//    }
//}
//public class Main {
//    public static void main(String[] args) {
//        Scanner sc=new Scanner(System.in);
//        System.out.print("请输入被除数：");
//        double dividend = sc.nextDouble();
//        System.out.print("请输入除数: ");
//        double divisor = sc.nextDouble();
//        if(divisor==0){
//            throw new DivisorIllegality("除数不能为0！");
//        }
//        System.out.println("输出结果为："+dividend/divisor);
//    }
//}

import com.sun.xml.internal.fastinfoset.tools.XML_SAX_StAX_FI;

import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc=new Scanner(System.in);
        int n=sc.nextInt();
        int[] dp=new int[n+1];
        dp[0]=1;
        dp[1]=1;
        dp[2]=2;

        for(int i=3;i<=n;i++){
            for(int j=0;j<i;j++){
                dp[i]+=dp[j]*dp[i-1-j];
            }
        }
        System.out.println(dp[n]);
    }
}
